… young mice exposed to six hours daily of a sound and light show reminiscent of a video game. The mice showed “dramatic changes everywhere in the brain,” said Jan-Marino Ramirez, director of the Center for Integrative Brain Research at Seattle Children’s Hospital.

“Many of those changes suggest that you have a brain that is wired up at a much more baseline excited level,” Ramirez reported. “You need much more sensory stimulation to get [the brain’s] attention.”

… On the plus side, it meant that these mice were able to stay calm in an environment that would have stressed out a typical mouse… But it also meant they acted like they had an attention deficit disorder, showed signs of learning problems, and were prone to risky behavior.

Overall, the results add to the evidence that parents should be very cautious about screen time for young children, Ramirez said. “I would minimize it.”

Leah Krubitzer, an evolutionary neurobiologist at the University of California, Davis: … It’s true this sort of stimulation may desensitize a child’s brain in some ways